[FFmpeg-devel] [PATCH v3] ffprobe: Add bits_per_component to stream output

[Stefano Sabatini]

On date Friday 2014-09-05 08:29:45 +0200, Tobias Rapp encoded:
> On 04.09.2014 17:39, wm4 wrote:
> >>diff --git a/libavutil/pixdesc.h b/libavutil/pixdesc.h
> >>index 41e81db..f8af18f 100644
> >>--- a/libavutil/pixdesc.h
> >>+++ b/libavutil/pixdesc.h
> >>@@ -251,6 +251,13 @@ int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc);
> >>  int av_get_padded_bits_per_pixel(const AVPixFmtDescriptor *pixdesc);
> >>
> >>  /**
> >>+ * Return the number of bits per component (bit depth) for the pixel format
> >>+ * described by pixdesc or 0 if the pixel format has unknown or non-uniform
> >>+ * bit depth.
> >>+ */
> >>+int av_get_bits_per_component(const AVPixFmtDescriptor *pixdesc);
> >>+
> >>+/**
> >>   * @return a pixel format descriptor for provided pixel format or NULL if
> >>   * this pixel format is unknown.
> >>   */
> >
> >
> >Does something such highly specialized really warrant its own API
> >function? There are several ways how to handle the case if the
> >component bit depths are not uniform, or even how the term "bit depth"
> >is to be interpreted, so IMO this should just be internal to ffprobe.
> 

> That would also be fine for me. Do you suggest to put it directly in
> ffprobe.c or cmdutils.c or some other file?

Alternatively, we expose the pixdesc information through a specific
ffprobe option (-show_pixel_descriptions?) so it can be processed by
the caller.

The problem with the current approach is that it leads to
inconsistency, the bits-per-component information is not really
related to the stream but is computed starting from the pix_fmt
information, which is duplicated in other parts of the ffprobe
output.

Having to process the output of ffprobe -show_pixel_descriptions may
require much work but would provide a more general solution (and it
would be useful for other purposes). Would that be acceptable to you?
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